1. Field of the Invention
The present invention relates to an improvement in an automobile front body structure.
2. Description of the Related Art
Shown schematically in FIG. 6 of the accompanying drawings is a conventional front body structure of an automobile. As shown in the figure, the structure includes a cranked front side frame 101 extending longitudinally of the automobile, with which a lower end of a dashboard lower 102 is adjoined, and upon which a floor plate 103 is placed. On the floor plate 103, a front seat 104 is installed. A subframe 106 is provided at a corner formed by the front side frame 101 and the dashboard lower 102.
A structure is known which is designed to release, through the subframe 106 into the dashboard lower 102, part of an external force applied to the automobile frontwise as indicated by an arrow 1 in circle.
FIG. 7 schematically shows, in top plan, only the main part of the structure of FIG. 6. The subframes 106, which have, for example, trapezoidal configurations as seen from above, are constructed such that local deformation of the dashboard lower 102 may be suppressed by dispersing applied forces as indicated by arrows 2 and 3 in circle.
However, as shown in FIG. 6, the front side frames 101, cranked as viewed from sideways, are bent downwardly at the lower end of the dashboard lower 102, thus exhibiting poor rigidity against external forces as indicated by arrow 1 in circle. In other words, since the front side frames 101 are not supported at their rear surfaces directly by the dashboard lower 102, efficiency of support by the dashboard lower 102 is low.
The present invention has been achieved to solve the above-described problem inherent to the conventional automobile front body structure.
The present inventor conducted a careful study to rationally unify requirements for increased rigidity and effective shock absorption by properly enhancing the rigidity of the joints between the front side frames and the dashboard lower and by rendering the joints deformable moderately so that a shock due to an external force is effectively absorbed.
As a result, the inventor found that the foregoing problem is overcome by providing a gusset between the front side frames and the dashboard lower, thus leading to the present invention. The inventor also found that the problem is overcome by taking the constitution, shape, and thickness of the gusset into account.
It is therefore an object of the present invention to provide an automobile front body structure which is adapted to rationally unify requirements for increased rigidity and effective shock absorption by properly enhancing the rigidity of the joints between front side frames and a dashboard lower and by rendering the joints deformable moderately so that a shock due to an external force is effectively absorbed.
It is another object of the present invention to provide an automobile front body structure which has desired rigidity and undergoes desired deformation under the action of an external force, that is, which produces a good shock absorbing effect.